Clamping-stem for bicycle handle-bars



C. E. WEAVER.

CLAMPING STEM FOB BICYCLE HANDLE BARS.

APPLICATION FILED MAYII, 1920.

1,364,496. I Patented Jan.4,1921.

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.UNITE-DSTATES PATENT OFFICE.

CHARLES E. WEAVER, OF CLEVELAND, OHIO, A-SSIGNOR 'IAO THE AMERICAN STOVE COMPANY, OF ST. LOUIS, MISSOURI, A CORPORATION.

CLAMPING-STEM FOR BICYCLE HANDLEjBARS.

6 State of Ohio, have invented certain new and useful Improvements in *Clamping-F Stems for Bicycle Handle-Bars, of which the following is a specification.

` My invention pertains to an improvement in a clamping stem for bicycle handle bars,

and the obj ect of the improvement is to provide a stem with an expanding shoe, and to construct these parts in a particular way to prevent them from slipping or turning when wedged within the tubular steering post of a'bicycle.

In the drawing accompanying this application, Figure l is a vertical sectional view of my improved stem shown in a wedged position within the head portion of a bicycle. Fig. 2 is a cross' section on line 2 2, Fig. 1.- Fig. 3 is a sideview on a reduced scale of my improvedmstem. Figs. 4 and 5 are `side land Sec-tional views of slightly modified formslof they invention.

The invention comprises a hollow tube or stem 2 having a suitable device at its upper end for fastening or clamping either-l ak one or two piece handle bar to the stem. In Fig. 1 I show an extension 3 with a split clampingv extremity 4 and a screw 5 to fasten a handle bar to the stem, and in Figs. 3 and 4 I show a serrated head 3 and a nut, and in Fig. 5 the upper end of 'the stem has a split head 5 which may be closed by bolt 9. The lower end of the stem is beveled on a straight line to provide a fiat surface 6 extending obliquely to the vertical axis of the stem, and a sliding shoe 7 of thev same'diameter as the stem `has acorresponding beveled Hat face or surface 8u whereby the said shoe may be seated and used as a straight extension yor,

prolongation of the stem. The clamping bolt or screw 9 serves to hold the shoe and stem together and a hexagonal head or enlargement 10 on the screw bears and rests upon the upper end of the stem and provides an exposed wrench-.engaging portion wherewith to turii the screw. The screwthreaded extremity 10 of this bolt or screw passes through the solid end of shoe 7 and when the screw is rotated the shoe cannot turn independently of the stem if thel fiat engaging faces 6 and' 8 are in contact; the

Specification of Letters Patent.

ling the stem and post rigidly together.

Patented J an. 4, 1.921.

Application flied may s, 1920. serial No. 379,724.

. result is that the shoe and stem are pressed out of axial alinement when the stem and shoe rest within the tubular steering post or fork 11 of the bicycle. The effect of this misalinement of the shoe and stem is to crowd and wedge the longer face 12 of the shoe and` the exterior vertical face 13 of the stem against the opposite sides or interior walls of the post 11, thereby lock- Wfith a smooth stem 'and shoe I find that locking of the stem within the post is not 1 effective to the degree required to prevent 'the stem from turning independentlypf the post under heavy strain or stress onthe 70. handle bar. Of course, the lockingof the stem within the post'might be made effective providing screw 9 was turned a suiiicient number of times to spread the Wedge and stem to an exceptional degree, but when this extreme yor excess action takes place several things are likely to happen: to wit,v the tubular post 1l is apt to swell or expand, itf may beinjured or ruptured, or

it may be caused to bind within the tubular bicycle head 14, or the screwthreads on the shoe .or screw may strip. To avoid such troubles and to obtain an effective lock against the turning or slipping of the stem within the steering post 11 I have serrated` or corrugated the external Surface of the] shoe 7 and these' corrugations extend longitudinally the full length of the shoe, and Imay use one or more exterior serrations -diametrically opposite the beveledl portion or the serrations may be placed annularly y opposite the beveled portion. y To make the lool; more effective I may also corrugate the 'lower extremity of stem 2, see Fig. 3. In Fig. 4L I show the lower extremity of stem 2 as serrated or corrugated longitudinally, particularly in the annular.- surface directly opposite the inclined wedging face 6, and in this view the shoe isshown as plainor'smooth. In Fig. 5 I show the lower extremity of stem 2 as plain or smooth, and shoe 7 is serrated or corrugated longitudinally. The serrations or corrugations arel preferably in the formof sharp ridges or teeth andI with their use the stem 2 may be locked against turning and slipping without endangering or injuring the steer ing tube or post. In this connection it should be understood that persons without mechanical sense or judgment, children for 110 example, are apt to apply a large Wrench bars, having a beveled extremity, a beveled 15 `\to the screw and turn it to excess, especially shoe, a tightening screw uniting said parts, lif they find that the stem 2 can Still be and the shoe being serrated upon its ex turned or rotated Within thepost and which teror opposite its beveled portion. 5 is possible Where the stem and shoe have a 3. A clamping stem lfor bicycle, handle smooth outer surface. bars, having a beveled extremity, a beveled 20 What I claim is: shoe, a tightening screw uniting1 said stem l. A clamping Stem for bicycle handle andscrew, and said stem and shoe having bars, having a beveled extremity and a their exterior surfaces serrated yopposite 10 separate beveled shoe united in slidable enthen1l respective beveled portions.

'gaging connection, one of said parts being Signed' at Los Angeles, in'the countyof 25 serrated upon its exterior opposite its bev- Los Angeles, and State of California, thisv eled portion. 21st day of April, 1920.

2. A clamping stem for bicycle handle l CHARLES E. WEAVER. 

